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Ecology
Describe the field of ecology
Question | Answer |
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Ecosystems | complex, interactive systems that include both biological communities (biotic) and physical (abiotic) components of the environment. |
Organisms and populations | organisms are dependent on their environmental interactions both with living and nonliving factors. |
Hierarchy | a hierarchical structure exists, Organism Groups of the same organisms (species) form populations, Different populations interact to form communities, Communities live within an ecosystem, and all of the ecosystems on Earth make up the biosphere. |
Energy | individual organisms, ecosystems are sustained by the continuous flow of energy. |
Changing ecosystems | Ecosystems are dynamic in nature; their characteristics can vary over time and disrupt to any physical or biological component of an ecosystem can lead to shifts in all its populations. |
Biodiversity | describes the variety of species found in Earth’s terrestrial and oceanic ecosystems. The completeness or integrity of an ecosystem’s biodiversity is often used as a measure of its health. |
Populations | a group of organisms belonging to the same species that live in a particular area. Populations can be described based on their size, density, or distribution. |
Population Density | Population density measures the number of individual organisms living in a defined space. |
Regulating Population Size | a population is affected by limiting factors that include density-dependent, density-independent, abiotic and biotic factors. |
Density-dependent factors | Limiting factors that are density-dependent are those that operate more strongly on large populations than on small ones. |
Density-independent factors | Limiting factors that are density-independent are those that occur regardless of how large the population is and reduce the size of all populations in the area in which they occur by the same proportion. |
Abiotic factors | are nonliving things in an ecosystem and may be chemical or physical. Some examples are water, nitrogen, oxygen, salinity, pH, soil nutrients and composition, temperature, amount of sunlight, and precipitation. |
Biotic factors | all of the living components of an ecosystem. Some examples are bacteria, fungi, plants, and animals. |
Changes in abiotic and biotic factors | A change in an abiotic or biotic factor may decrease the size of a population if it cannot acclimate or adapt to or migrate from the change. |